21323013600 has 288 divisors, whose sum is σ = 80625839616. Its totient is φ = 4793702400.

The previous prime is 21323013563. The next prime is 21323013617. The reversal of 21323013600 is 631032312.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1014397 + ... + 1035203.

It is an arithmetic number, because the mean of its divisors is an integer number (279950832).

Almost surely, 2^21323013600 is an apocalyptic number.

21323013600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21323013600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40312919808).

21323013600 is an abundant number, since it is smaller than the sum of its proper divisors (59302826016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21323013600 is a wasteful number, since it uses less digits than its factorization.

21323013600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20898 (or 20885 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21323013600 its reverse (631032312), we get a palindrome (21954045912).

The spelling of 21323013600 in words is "twenty-one billion, three hundred twenty-three million, thirteen thousand, six hundred".